Photosensitive Resin and Manufacturing Method Thereof

ABSTRACT

Various embodiments disclosed relate to photopolymerizable compositions that are suitable for making three-dimensional structures when exposed to laser light.

BACKGROUND

Most conventional photosensitive resins do not work in chip-basedholographic imaging systems. There is a therefore a need forphotosensitive resin compositions with the necessary optical propertiesthat allow for precise control of photon flux and photoinitiation rate.

SUMMARY OF THE INVENTION

In various embodiments, a composition including at least one urethaneacrylate monomer, at least one pentaerythritol acrylate monomer, atleast one polyester acrylate resin, and at least one photoinitiator isprovided.

In various embodiments, a composition comprising about 40 wt % of analiphatic urethane diacrylate monomer, about 40 wt % of an ethoxylatedpentaerythritol tetraacrylate monomer, about 20 wt % of a thiolsubstituted polyester acrylate resin, and at least one metallocenephotoinitiator having the structure:

is provided.

In various embodiments, a method of making a polymerizable compositionis provided. The method includes combining at least one monomercomprising urethane acrylate, at least one monomer comprisingpentaerythritol acrylate, and at least one polyester acrylate resin toform a homogenous mixture, combining the homogenous mixture with a photoinitiator to form an initial mixture, and stirring the initial mixtureat a temperature greater than about 30° C.

In various embodiments, a method of holographic printing is provided.The method includes projecting a hologram into at least a portion of acomposition comprising at least one monomer urethane acrylate, at leastone monomer pentaerythritol acrylate, at least one polyester acrylateresin, and at least one photo initiator, and polymerizing thecomposition substantially in the shape of the hologram.

Advantageously, the compositions herein are capable of polymerizing inthe presence of laser light in a short period to form solid objects thatare ready for use.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to certain embodiments of thedisclosed subject matter. While the disclosed subject matter will bedescribed in conjunction with the enumerated claims, it will beunderstood that the exemplified subject matter is not intended to limitthe claims to the disclosed subject matter.

In various embodiments, a composition containing at least one urethaneacrylate, at least one monomer including pentaerythritol acrylate, atleast one polyester acrylate resin, and at least one photo initiator isprovided. In various embodiments, the urethane acrylate, thepentaerythritol acrylate, and the polyester acrylate resin are notphotosensitive and do not polymerize under UVA or UVB light.

The urethane acrylate can be an oligomer or a monomer. In variousembodiments, the urethane acrylate is a monomer. The urethane acrylatecan be present in an amount of about 30 wt % to about 70 wt %, about 35wt % to about 70 wt %, about 40 wt % to about 70 wt %, about 45 wt % toabout 70 wt %, about 50 wt % to about 70 wt %, about 30 wt % to about 65wt %, about 30 wt % to about 60 wt %, about 30 wt % to about 55 wt %, orabout 30 wt % to about 50 wt %, relative to the total weight of thecomposition. The urethane acrylate can be present in an amount of about30 wt %, 35 wt %, 40 wt %, 45 wt %, 50 wt %, 55 wt %, 60 wt %, 65 wt %,or 70 wt %. The urethane acrylate can be monofunctional, difunctional,or trifunctional, and can be aliphatic or aromatic. Monofunctionalurethane acrylates possess a urethane backbone and one acrylatefunctionality. Di and tri functional acrylates possess two and threeacrylate functional groups respectively attached to at least oneurethane component as the backbone. In various embodiments, the urethaneacrylate is an aliphatic urethane diacrylate. The aliphatic urethanediacrylate can also be a polyether, polyester, or polyether/polyesterbased urethane diacrylate. Suitable oligomeric urethane acrylatesinclude, but are not limited to, urethane acrylates with product codesCN9001 NS, CN9006 NS, CN9007, CN9010 NS, CN9013 NS, CN9014 NS, CN9021NS, CN910A70, CN9110 NS, CN9167, CN9178 NS, CN959, CN963B80, CN964,CN965 NS, CN966H90 NS, CN966J75 NS, CN969 NS, CN970A60 NS, CN971A80,CN975 NS, CN978 NS, CN980 NS, CN981 NS, CN981B88 NS, CN983 NS, CN985B88,CN989 NS, CN9893 NS, CN991 NS, and CN996 NS available from SartomerArkema group.

In various embodiments, the pentaerythritol acrylate can be apentaerythritol monoacrylate, pentaerythritol diacrylate,pentaerythritol triacrylate, or pentaerythritol tetraacrylate. Invarious embodiments, the pentaerythritol acrylate is pentaerythritoltetraacrylate. The pentaerythritol acrylate can also be ethoxylated, andany one of the pentaerythritol mono-, di-, tri-, or tertaacrylates canbe ethoxylated. For example, ethoxylated pentaerythritol tetraacrylatecan have the following structure:

Variables a, b, c, and d can each independently range from 0 to 20.

In various embodiments the pentaerythritol acrylate is present in anamount of about 20 wt % to about 60 wt %, about 30 wt % to about 50 wt%, or about 35 wt % to about 45 wt %. The pentaerythritol acrylate canbe present in about 20 wt %, 25 wt %, 30 wt %, 35 wt %, 40 wt %, 45 wt%, or 50 wt %, or any range or sub-range between these values.

The polyester acrylate resin can be include one or more thiol groups.Suitable polyester acrylate resins include, but are not limited to,Ebecryl® LED 02 and Thiocure TMPMP (trimethylolpropanetri(3-mercaptopropionate)), in which the mercapto functionality takesthe form of R—S—H where R is a mono, di, or tri functional polymerizableacrylate.

In various embodiments, the thiol groups in the polyester acrylate canderive from, for example, covalent attachment of L-cysteine to thepolyester acrylate. In various embodiments, the thiol groups in thepolyester acrylate can scavenge reactive oxygen species that wouldotherwise terminate the radical polymerization. The thiol-containingpolyester acrylate can, in various embodiments, impart improved surfacecure to the printed object.

The polyester acrylate resin containing one or more thiol groups can bepresent in an amount of about 5 wt % to about 40 wt %, about 10 wt % toabout 30 wt %, or about 15 wt % to about 25 wt %, or any range orsub-range between these values. In various embodiments, the polyesteracrylate resin containing one or more thiol groups can be present in anamount of about 5 wt %, 10 wt %, 15 wt %, 20 wt %, 25 wt %, 30 wt %, 35wt %, or 40 wt %, or any range or sub-range between these values.

In various embodiments, the photo initiator has the formula I

where M is a transition metal, L¹, L², L³, and L⁴ are each independentlyalkyl, aryl, alkylaryl, or heteroaryl, each of which is substituted orunsubstituted. Suitable transition metals can include Sc, Ti, V, Cr, Mn,Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, La, Hf, Ta,W, Re, Os, Ir, Pt, Au, and Hg. In various embodiments L¹ and L² areidentical ligands coordinated to metal M. In various embodiments, L³ andL⁴ are identical ligands coordinated to metal M.

In various embodiments, M is titanium (Ti). In various embodiments, L¹is substituted or unsubstituted cyclopentadienyl. When, ligand L¹ is asubstituted cyclopentadienyl, it can have one, two, three, four, or fivesubstitutions on the cyclopentadienyl ring. Each substitution can beindependently alkyl, aryl, aralkyl, halogen, or heteroaryl as definedherein. In various embodiments, L¹ is cyclopentadienyl (C₅H₅).

In various embodiments, L³ is substituted aryl. The aryl can be a phenylmoiety. Ligand L³ can have one, two, three, four, or five substitutionson the aryl ring. Each substitution can be independently alkyl, aryl,aralkyl, halogen, or heteroaryl as defined herein. In variousembodiments, L³ has the structure

In various embodiments, the photo initiator has the structure

In various embodiments, the photo initiator is present in an amount offrom about 0.01 wt % to about 5 wt %, about 0.01 wt % to about 4 wt %,about 0.01 wt % to about 3 wt %, about 0.01 wt % about 2 wt %, about0.01 wt % to about 1 wt %, about 0.05 wt % to about 0.9 wt %, about 0.1wt % to about 0.8 wt %, about 0.2 wt % to about 0.7 wt %, about 0.3 wt %to about 0.6 wt %, or any range or sub-range between these values. Invarious embodiments, the photo initiator is present in an amount ofabout 0.01 wt %, 0.025 wt %, 0.05 wt %, 0.075 wt %, 0.1 wt %, 0.15 wt %,0.2 wt %, 0.25 wt %, 0.3 wt %, 0.35 wt %, 0.4 wt %, 0.45 wt %, or 0.5 wt%.

In various embodiments, the composition includes about 40 wt % of analiphatic urethane diacrylate monomer, about 40 wt % of an ethoxylatedpentaerythritol tetraacrylate monomer, about 20 wt % of a thiolsubstituted polyester acrylate resin; and at least one photo initiatorhaving the structure

In various embodiments, a method of making a polymerizable compositionincludes combining at least one urethane acrylate monomer, at least onepentaerythritol acrylate monomer, and at least one polyester acrylateresin to form a homogenous mixture, combining the homogenous mixturewith a photo initiator to form an initial mixture, and stirring theinitial mixture at a temperature greater than about 30° C.

In various embodiments, the initial mixture is stirred at a temperatureof about 35° C. to about 50° C., about 37° C. to about 47° C., about 38°C. to about 46° C., about 39° C. to about 45° C., or any range orsub-range in between these values. In various embodiments, the initialmixture is stirred at a temperature of about 31° C., 32° C., 33° C., 34°C., 35° C., 36° C., 37° C., 38° C., 39° C., 40° C., 41° C., 42° C., 43°C., 44° C., 45° C., 46° C., 47° C., 48° C., 49° C., 50° C., or any rangeor sub-range between these values.

In various embodiments, the initial mixture is stirred for a period ofabout 20 minutes to about 3 hours, about 30 minutes to about 2.5 hours,about 40 minutes to about 2 hours, about 45 minutes to about 1.5 hours,about 50 minutes to about 1.25 hours, or any range or sub-range betweenthese values. In various embodiments, the initial mixture is stirred forabout 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45minutes, 50 minutes, 55 minutes, 60 minutes, or any range or sub-rangebetween these values.

In various embodiments, a method of polymerizing a composition includesexposing a composition that includes at least one urethane acrylatemonomer, at least one pentaerythritol acrylate monomer, at least onepolyester acrylate resin, and at least one photo initiator to laserlight. The laser light can be light generated from any suitable lasersource that emits one or more wavelengths within one or more absorptionbands of the photoinitiator. Suitable laser sources can includesolid-state lasers, fiber lasers, semiconductor lasers, dye lasers, andfree electron lasers. In various embodiments, the laser light has awavelength ranging from about 400 nm to about 540 nm, about 420 nm toabout 540 nm, about 440 nm to about 540 nm, about 460 nm to about 540nm, or about 480 nm to about 540 nm. In various embodiments, the laserlight has a wavelength of about 485 nm to about 520 nm, about 490 nm toabout 510 nm, about 495 nm to about 505 nm, or any range or sub-rangebetween these values. In various embodiments, the laser light has awavelength of about 400 nm, 410 nm, 420 nm, 430 nm, 440 nm, 450 nm, 460nm, 470 nm, 485 nm, 487 nm, 489 nm, 491 nm, 493 nm, 495 nm, 497 nm, 499nm, 501 nm, 503 nm, 505 nm, 507 nm, 509 nm, 511 nm, 513 nm, 515 nm, 517nm, 519 nm, 521 nm, 523 nm, 525 nm, 527 nm, 529 nm, 535 nm, or 540 nm.

In various embodiments, the laser light has an intensity ranging fromabout 1 mW/cm² to about 200 mW/cm², about 5 mW/cm² to about 190 mW/cm²,about 10 mW/cm² to about 180 mW/cm², about 20 mW/cm² to about 170mW/cm², about 30 mW/cm² to about 160 mW/cm², about 40 mW/cm² to about150 mW/cm², about 50 mW/cm² to about 140 mW/cm², about 60 mW/cm² toabout 130 mW/cm², about 70 mW/cm² to about 120 mW/cm², about 80 mW/cm²to about 110 mW/cm², or any range or sub-range between these values. Invarious embodiments, the laser light has an intensity of about 1 mW/cm²,5 mW/cm², 10 mW/cm², 15 mW/cm², 20 mW/cm², 25 mW/cm², 30 mW/cm², 35mW/cm², 40 mW/cm², 45 mW/cm², 50 mW/cm², 55 mW/cm², 60 mW/cm², 65mW/cm², 70 mW/cm², 75 mW/cm², 80 mW/cm², 85 mW/cm², 90 mW/cm², 95mW/cm², 100 mW/cm², or any range or sub-range in between these values.

In various embodiments, the polymerizable composition is subjected tothe light for a period of about 10 seconds to about 120 seconds, about15 seconds to about 110 seconds, about 20 seconds to about 100 seconds,about 25 seconds to about 90 seconds, about 30 seconds to about 80seconds, about 35 seconds to about 70 seconds, about 40 seconds to about60 seconds, or any range or sub range in between these values. Invarious embodiments, the polymerizable composition is subjected to thelight for a period of about 10 seconds, 15 seconds, 20 seconds, 25seconds, 30 seconds, 35 seconds, 40 seconds, 45 seconds, 50 seconds, 55seconds, 60 seconds, or any range or sub-range in between these values.

In various embodiments, the laser light has a wavelength ranging fromabout 400 nm to about 540 nm. In various embodiments, the laser lighthas a wavelength of about 510 nm.

In various embodiments, a method of holographic printing, is provided.The method includes projecting a hologram or three dimensionalvolumetric wavefront into at least a portion of any one of thecompositions described herein and polymerizing the compositionsubstantially in the shape of the hologram. In various embodiments, thehologram includes laser light with a wavelength ranging from about 400nm to about 530 nm.

Examples

Various embodiments of the present invention can be better understood byreference to the following Examples which are offered by way ofillustration. The present invention is not limited to the Examples givenherein.

Synthesis of Photosensitive Resin Composition

Aliphatic urethane acrylate (79.92 grams, 39.96 wt %), ethoxylatedpentaerythritol tetraacylate (79.92 grams, 39.96 wt %), thiol modifiedresin (39.96 grams, 19.98 wt %) were added to a pyrex glass containerand mixed until a homogenous mixture was formed. Bis(2,6-difluoro-3-(1-hydropyrro-1-yl)-phenyl)titanocene (200 mg, 0.1 wt %)was added to the homogenous mixture in the absence of light, and thefinal mixture was stirred at 40° C. for 1 hour, then cooled to roomtemperature. After cooling, the mixture is ready to use for holographicprinting or can be stored in the absence of light at room temperaturefor later use.

Holographic Printing

The liquid mixture described above is placed into a container, and amesh support structure is also placed in the container. The liquidmixture is exposed to a hologram projected using green laser light,which forms a three-dimensional holographic image in the liquid mixture.The holograms can be created using a silicon wafer having on it a tinygrid of tunable crystals that can be used to control the magnitude andtime delay, or phase, of reflected light shined at the surface of thechip from a laser. Software can adjust the crystals to create patternsof interference in the light, resulting in a three-dimensional lightfield. After the liquid mixture is exposed to the holographic image forabout 5-10 seconds, a three-dimensional object is formed in the liquidmixture on top of the mesh support as a result of the photo inducedpolymerization of the liquid mixture by the laser light. The meshsupport can be removed from the liquid mixture to reveal the fullyformed three-dimensional object with substantially the same shape as thehologram.

The terms and expressions that have been employed are used as terms ofdescription and not of limitation, and there is no intention in the useof such terms and expressions of excluding any equivalents of thefeatures shown and described or portions thereof, but it is recognizedthat various modifications are possible within the scope of theembodiments of the present invention. Thus, it should be understood thatalthough the present invention has been specifically disclosed byspecific embodiments and optional features, modification and variationof the concepts herein disclosed may be resorted to by those of ordinaryskill in the art, and that such modifications and variations areconsidered to be within the scope of embodiments of the presentinvention.

Throughout this document, values expressed in a range format should beinterpreted in a flexible manner to include not only the numericalvalues explicitly recited as the limits of the range, but also toinclude all the individual numerical values or sub-ranges encompassedwithin that range as if each numerical value and sub-range is explicitlyrecited. For example, a range of “about 0.1% to about 5%” or “about 0.1%to 5%” should be interpreted to include not just about 0.1% to about 5%,but also the individual values (e.g., 1%, 2%, 3%, and 4%) and thesub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within theindicated range. The statement “about X to Y” has the same meaning as“about X to about Y,” unless indicated otherwise. Likewise, thestatement “about X, Y, or about Z” has the same meaning as “about X,about Y, or about Z,” unless indicated otherwise.

In this document, the terms “a,” “an,” or “the” are used to include oneor more than one unless the context clearly dictates otherwise. The term“or” is used to refer to a nonexclusive “or” unless otherwise indicated.The statement “at least one of A and B” or “at least one of A or B” hasthe same meaning as “A, B, or A and B.” In addition, it is to beunderstood that the phraseology or terminology employed herein, and nototherwise defined, is for the purpose of description only and not oflimitation. Any use of section headings is intended to aid reading ofthe document and is not to be interpreted as limiting; information thatis relevant to a section heading may occur within or outside of thatparticular section.

In the methods described herein, the acts can be carried out in anyorder without departing from the principles of the invention, exceptwhen a temporal or operational sequence is explicitly recited.Furthermore, specified acts can be carried out concurrently unlessexplicit claim language recites that they be carried out separately. Forexample, a claimed act of doing X and a claimed act of doing Y can beconducted simultaneously within a single operation, and the resultingprocess will fall within the literal scope of the claimed process.

The term “about” as used herein can allow for a degree of variability ina value or range, for example, within 10%, within 5%, or within 1% of astated value or of a stated limit of a range, and includes the exactstated value or range.

The term “substantially” as used herein refers to a majority of, ormostly, as in at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%,98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more, or100%. The term “substantially free of” as used herein can mean havingnone or having a trivial amount of, such that the amount of materialpresent does not affect the material properties of the compositionincluding the material, such that the composition is about 0 wt % toabout 5 wt % of the material, or about 0 wt % to about 1 wt %, or about5 wt % or less, or less than, equal to, or greater than about 4.5 wt %,4, 3.5, 3, 2.5, 2, 1.5, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1,0.01, or about 0.001 wt % or less. The term “substantially free of” canmean having a trivial amount of, such that a composition is about 0 wt %to about 5 wt % of the material, or about 0 wt % to about 1 wt %, orabout 5 wt % or less, or less than, equal to, or greater than about 4.5wt %, 4, 3.5, 3, 2.5, 2, 1.5, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2,0.1, 0.01, or about 0.001 wt % or less, or about 0 wt %.

The term “substituted” as used herein in conjunction with a molecule oran organic group as defined herein refers to the state in which one ormore hydrogen atoms contained therein are replaced by one or morenon-hydrogen atoms. The term “functional group” or “substituent” as usedherein refers to a group that can be or is substituted onto a moleculeor onto an organic group. Examples of substituents or functional groupsinclude, but are not limited to, a halogen (e.g., F, Cl, Br, and I); anoxygen atom in groups such as hydroxy groups, alkoxy groups, aryloxygroups, aralkyloxy groups, oxo(carbonyl) groups, carboxyl groupsincluding carboxylic acids, carboxylates, and carboxylate esters; asulfur atom in groups such as thiol groups, alkyl and aryl sulfidegroups, sulfoxide groups, sulfone groups, sulfonyl groups, andsulfonamide groups; a nitrogen atom in groups such as amines,hydroxyamines, nitriles, nitro groups, N-oxides, hydrazides, azides, andenamines; and other heteroatoms in various other groups. Non-limitingexamples of substituents that can be bonded to a substituted carbon (orother) atom include F, Cl, Br, I, OR, OC(O)N(R)₂, CN, NO, NO₂, ONO₂,azido, CF₃, OCF₃, R, O (oxo), S (thiono), C(O), S(O), methylenedioxy,ethylenedioxy, N(R)₂, SR, SOR, SO₂R, SO₂N(R)₂, SO₃R, C(O)R, C(O)C(O)R,C(O)CH₂C(O)R, C(S)R, C(O)OR, OC(O)R, C(O)N(R)₂, OC(O)N(R)₂, C(S)N(R)₂,(CH₂)₀₋₂N(R)C(O)R, (CH₂)₀₋₂N(R)N(R)₂, N(R)N(R)C(O)R, N(R)N(R)C(O)OR,N(R)N(R)CON(R)₂, N(R)SO₂R, N(R)SO₂N(R)₂, N(R)C(O)OR, N(R)C(O)R,N(R)C(S)R, N(R)C(O)N(R)₂, N(R)C(S)N(R)₂, N(COR)COR, N(OR)R, C(═NH)N(R)₂,C(O)N(OR)R, and C(═NOR)R, wherein R can be hydrogen or a carbon-basedmoiety; for example, R can be hydrogen, (C₁-C₁₀₀)hydrocarbyl, alkyl,acyl, cycloalkyl, aryl, aralkyl, heterocyclyl, heteroaryl, orheteroarylalkyl; or wherein two R groups bonded to a nitrogen atom or toadjacent nitrogen atoms can together with the nitrogen atom or atomsform a heterocyclyl.

The term “alkyl” as used herein refers to straight chain and branchedalkyl groups and cycloalkyl groups having from 1 to 40 carbon atoms, 1to about 20 carbon atoms, 1 to 12 carbons or, in various embodiments,from 1 to 8 carbon atoms. Examples of straight chain alkyl groupsinclude those with from 1 to 8 carbon atoms such as methyl, ethyl,n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, and n-octyl groups.Examples of branched alkyl groups include, but are not limited to,isopropyl, iso-butyl, sec-butyl, t-butyl, neopentyl, isopentyl, and2,2-dimethylpropyl groups. As used herein, the term “alkyl” encompassesn-alkyl, isoalkyl, and anteisoalkyl groups as well as other branchedchain forms of alkyl. Representative substituted alkyl groups can besubstituted one or more times with any of the groups listed herein, forexample, amino, hydroxy, cyano, carboxy, nitro, thio, alkoxy, andhalogen groups.

The term “alkenyl” as used herein refers to straight and branched chainand cyclic alkyl groups as defined herein, except that at least onedouble bond exists between two carbon atoms. Thus, alkenyl groups havefrom 2 to 40 carbon atoms, or 2 to about 20 carbon atoms, or 2 to 12carbon atoms or, in various embodiments, from 2 to 8 carbon atoms.Examples include, but are not limited to vinyl, —CH═CH(CH₃),—CH═C(CH₃)₂, —C(CH₃)═CH₂, —C(CH₃)═CH(CH₃), —C(CH₂CH₃)═CH₂, cyclohexenyl,cyclopentenyl, cyclohexadienyl, butadienyl, pentadienyl, and hexadienylamong others.

The term “alkynyl” as used herein refers to straight and branched chainalkyl groups, except that at least one triple bond exists between twocarbon atoms. Thus, alkynyl groups have from 2 to 40 carbon atoms, 2 toabout 20 carbon atoms, or from 2 to 12 carbons or, in variousembodiments, from 2 to 8 carbon atoms. Examples include, but are notlimited to —C≡CH, —C≡C(CH₃), —C≡C(CH₂CH₃), —CH₂C≡CH, —CH₂C≡C(CH₃), and—CH₂C≡C(CH₂CH₃) among others.

The term “acyl” as used herein refers to a group containing a carbonylmoiety wherein the group is bonded via the carbonyl carbon atom. Thecarbonyl carbon atom is bonded to a hydrogen forming a “formyl” group oris bonded to another carbon atom, which can be part of an alkyl, aryl,aralkyl cycloalkyl, cycloalkylalkyl, heterocyclyl, heterocyclylalkyl,heteroaryl, heteroarylalkyl group or the like. An acyl group can include0 to about 12, 0 to about 20, or 0 to about 40 additional carbon atomsbonded to the carbonyl group. An acyl group can include double or triplebonds within the meaning herein. An acryloyl group is an example of anacyl group. An acyl group can also include heteroatoms within themeaning herein. A nicotinoyl group (pyridyl-3-carbonyl) is an example ofan acyl group within the meaning herein. Other examples include acetyl,benzoyl, phenylacetyl, pyridylacetyl, cinnamoyl, and acryloyl groups andthe like. When the group containing the carbon atom that is bonded tothe carbonyl carbon atom contains a halogen, the group is termed a“haloacyl” group. An example is a trifluoroacetyl group.

The term “cycloalkyl” as used herein refers to cyclic alkyl groups suchas, but not limited to, cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl, and cyclooctyl groups. In various embodiments,the cycloalkyl group can have 3 to about 8-12 ring members, whereas inother embodiments the number of ring carbon atoms range from 3 to 4, 5,6, or 7. Cycloalkyl groups further include polycyclic cycloalkyl groupssuch as, but not limited to, norbornyl, adamantyl, bornyl, camphenyl,isocamphenyl, and carenyl groups, and fused rings such as, but notlimited to, decalinyl, and the like. Cycloalkyl groups also includerings that are substituted with straight or branched chain alkyl groupsas defined herein. Representative substituted cycloalkyl groups can bemono-substituted or substituted more than once, such as, but not limitedto, 2,2-, 2,3-, 2,4-2,5- or 2,6-disubstituted cyclohexyl groups ormono-, di- or tri-substituted norbornyl or cycloheptyl groups, which canbe substituted with, for example, amino, hydroxy, cyano, carboxy, nitro,thio, alkoxy, and halogen groups. The term “cycloalkenyl” alone or incombination denotes a cyclic alkenyl group.

The term “aryl” as used herein refers to cyclic aromatic hydrocarbongroups that do not contain heteroatoms in the ring. Thus aryl groupsinclude, but are not limited to, phenyl, azulenyl, heptalenyl, biphenyl,indacenyl, fluorenyl, phenanthrenyl, triphenylenyl, pyrenyl,naphthacenyl, chrysenyl, biphenylenyl, anthracenyl, and naphthyl groups.In various embodiments, aryl groups contain about 6 to about 14 carbonsin the ring portions of the groups. Aryl groups can be unsubstituted orsubstituted, as defined herein. Representative substituted aryl groupscan be mono-substituted or substituted more than once, such as, but notlimited to, a phenyl group substituted at any one or more of 2-, 3-, 4-,5-, or 6-positions of the phenyl ring, or a naphthyl group substitutedat any one or more of 2- to 8-positions thereof.

The term “aralkyl” as used herein refers to alkyl groups as definedherein in which a hydrogen or carbon bond of an alkyl group is replacedwith a bond to an aryl group as defined herein. Representative aralkylgroups include benzyl and phenylethyl groups and fused(cycloalkylaryl)alkyl groups such as 4-ethyl-indanyl. Aralkenyl groupsare alkenyl groups as defined herein in which a hydrogen or carbon bondof an alkyl group is replaced with a bond to an aryl group as definedherein.

The term “heterocyclyl” as used herein refers to aromatic andnon-aromatic ring compounds containing three or more ring members, ofwhich one or more is a heteroatom such as, but not limited to, N, O, andS. Thus, a heterocyclyl can be a cycloheteroalkyl, or a heteroaryl, orif polycyclic, any combination thereof. In various embodiments,heterocyclyl groups include 3 to about 20 ring members, whereas othersuch groups have 3 to about 15 ring members. A heterocyclyl groupdesignated as a C₂-heterocyclyl can be a 5-ring with two carbon atomsand three heteroatoms, a 6-ring with two carbon atoms and fourheteroatoms and so forth. Likewise a C₄-heterocyclyl can be a 5-ringwith one heteroatom, a 6-ring with two heteroatoms, and so forth. Thenumber of carbon atoms plus the number of heteroatoms equals the totalnumber of ring atoms. A heterocyclyl ring can also include one or moredouble bonds. A heteroaryl ring is an embodiment of a heterocyclylgroup. The phrase “heterocyclyl group” includes fused ring speciesincluding those that include fused aromatic and non-aromatic groups. Forexample, a dioxolanyl ring and a benzdioxolanyl ring system(methylenedioxyphenyl ring system) are both heterocyclyl groups withinthe meaning herein. The phrase also includes polycyclic ring systemscontaining a heteroatom such as, but not limited to, quinuclidyl.Heterocyclyl groups can be unsubstituted, or can be substituted asdiscussed herein. Heterocyclyl groups include, but are not limited to,pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, pyrrolyl,pyrazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, thiazolyl,pyridinyl, thiophenyl, benzothiophenyl, benzofuranyl,dihydrobenzofuranyl, indolyl, dihydroindolyl, azaindolyl, indazolyl,benzimidazolyl, azabenzimidazolyl, benzoxazolyl, benzothiazolyl,benzothiadiazolyl, imidazopyridinyl, isoxazolopyridinyl,thianaphthalenyl, purinyl, xanthinyl, adeninyl, guaninyl, quinolinyl,isoquinolinyl, tetrahydroquinolinyl, quinoxalinyl, and quinazolinylgroups. Representative substituted heterocyclyl groups can bemono-substituted or substituted more than once, such as, but not limitedto, piperidinyl or quinolinyl groups, which are 2-, 3-, 4-, 5-, or6-substituted, or disubstituted with groups such as those listed herein.

The term “heteroaryl” as used herein refers to aromatic ring compoundscontaining 5 or more ring members, of which, one or more is a heteroatomsuch as, but not limited to, N, O, and S; for instance, heteroaryl ringscan have 5 to about 8-12 ring members. A heteroaryl group is a varietyof a heterocyclyl group that possesses an aromatic electronic structure.A heteroaryl group designated as a C₂-heteroaryl can be a 5-ring withtwo carbon atoms and three heteroatoms, a 6-ring with two carbon atomsand four heteroatoms and so forth. Likewise a C₄-heteroaryl can be a5-ring with one heteroatom, a 6-ring with two heteroatoms, and so forth.The number of carbon atoms plus the number of heteroatoms sums up toequal the total number of ring atoms. Heteroaryl groups include, but arenot limited to, groups such as pyrrolyl, pyrazolyl, triazolyl,tetrazolyl, oxazolyl, isoxazolyl, thiazolyl, pyridinyl, thiophenyl,benzothiophenyl, benzofuranyl, indolyl, azaindolyl, indazolyl,benzimidazolyl, azabenzimidazolyl, benzoxazolyl, benzothiazolyl,benzothiadiazolyl, imidazopyridinyl, isoxazolopyridinyl,thianaphthalenyl, purinyl, xanthinyl, adeninyl, guaninyl, quinolinyl,isoquinolinyl, tetrahydroquinolinyl, quinoxalinyl, and quinazolinylgroups. Heteroaryl groups can be unsubstituted, or can be substitutedwith groups as is discussed herein. Representative substitutedheteroaryl groups can be substituted one or more times with groups suchas those listed herein.

Additional examples of aryl and heteroaryl groups include but are notlimited to phenyl, biphenyl, indenyl, naphthyl (1-naphthyl, 2-naphthyl),N-hydroxytetrazolyl, N-hydroxytriazolyl, N-hydroxyimidazolyl,anthracenyl (1-anthracenyl, 2-anthracenyl, 3-anthracenyl), thiophenyl(2-thienyl, 3-thienyl), furyl (2-furyl, 3-furyl), indolyl, oxadiazolyl,isoxazolyl, quinazolinyl, fluorenyl, xanthenyl, isoindanyl, benzhydryl,acridinyl, thiazolyl, pyrrolyl (2-pyrrolyl), pyrazolyl (3-pyrazolyl),imidazolyl (1-imidazolyl, 2-imidazolyl, 4-imidazolyl, 5-imidazolyl),triazolyl (1,2,3-triazol-1-yl, 1,2,3-triazol-2-yl 1,2,3-triazol-4-yl,1,2,4-triazol-3-yl), oxazolyl (2-oxazolyl, 4-oxazolyl, 5-oxazolyl),thiazolyl (2-thiazolyl, 4-thiazolyl, 5-thiazolyl), pyridyl (2-pyridyl,3-pyridyl, 4-pyridyl), pyrimidinyl (2-pyrimidinyl, 4-pyrimidinyl,5-pyrimidinyl, 6-pyrimidinyl), pyrazinyl, pyridazinyl (3-pyridazinyl,4-pyridazinyl, 5-pyridazinyl), quinolyl (2-quinolyl, 3-quinolyl,4-quinolyl, 5-quinolyl, 6-quinolyl, 7-quinolyl, 8-quinolyl), isoquinolyl(1-isoquinolyl, 3-isoquinolyl, 4-isoquinolyl, 5-isoquinolyl,6-isoquinolyl, 7-isoquinolyl, 8-isoquinolyl), benzo[b]furanyl(2-benzo[b]furanyl, 3-benzo[b]furanyl, 4-benzo[b]furanyl,5-benzo[b]furanyl, 6-benzo[b]furanyl, 7-benzo[b]furanyl),2,3-dihydro-benzo[b]furanyl (2-(2,3-dihydro-benzo[b]furanyl),3-(2,3-dihydro-benzo[b]furanyl), 4-(2,3-dihydro-benzo[b]furanyl),5-(2,3-dihydro-benzo[b]furanyl), 6-(2,3-dihydro-benzo[b]furanyl),7-(2,3-dihydro-benzo[b]furanyl), benzo[b]thiophenyl(2-benzo[b]thiophenyl, 3-benzo[b]thiophenyl, 4-benzo[b]thiophenyl,5-benzo[b]thiophenyl, 6-benzo[b]thiophenyl, 7-benzo[b]thiophenyl),2,3-dihydro-benzo[b]thiophenyl, (2-(2,3-dihydro-benzo[b]thiophenyl),3-(2,3-dihydro-benzo[b]thiophenyl), 4-(2,3-dihydro-benzo[b]thiophenyl),5-(2,3-dihydro-benzo[b]thiophenyl), 6-(2,3-dihydro-benzo[b]thiophenyl),7-(2,3-dihydro-benzo[b]thiophenyl), indolyl (1-indolyl, 2-indolyl,3-indolyl, 4-indolyl, 5-indolyl, 6-indolyl, 7-indolyl), indazole(1-indazolyl, 3-indazolyl, 4-indazolyl, 5-indazolyl, 6-indazolyl,7-indazolyl), benzimidazolyl (1-benzimidazolyl, 2-benzimidazolyl,4-benzimidazolyl, 5-benzimidazolyl, 6-benzimidazolyl, 7-benzimidazolyl,8-benzimidazolyl), benzoxazolyl (1-benzoxazolyl, 2-benzoxazolyl),benzothiazolyl (1-benzothiazolyl, 2-benzothiazolyl, 4-benzothiazolyl,5-benzothiazolyl, 6-benzothiazolyl, 7-benzothiazolyl), carbazolyl(1-carbazolyl, 2-carbazolyl, 3-carbazolyl, 4-carbazolyl),5H-dibenz[b,f]azepine (5H-dibenz[b,f]azepin-1-yl,5H-dibenz[b,f]azepine-2-yl, 5H-dibenz[b,f]azepine-3-yl,5H-dibenz[b,f]azepine-4-yl, 5H-dibenz[b,f]azepine-5-yl),10,11-dihydro-5H-dibenz[b,f]azepine(10,11-dihydro-5H-dibenz[b,f]azepine-1-yl,10,11-dihydro-5H-dibenz[b,f]azepine-2-yl,10,11-dihydro-5H-dibenz[b,f]azepine-3-yl,10,11-dihydro-5H-dibenz[b,f]azepine-4-yl,10,11-dihydro-5H-dibenz[b,f]azepine-5-yl), and the like.

The term “heterocyclylalkyl” as used herein refers to alkyl groups asdefined herein in which a hydrogen or carbon bond of an alkyl group asdefined herein is replaced with a bond to a heterocyclyl group asdefined herein. Representative heterocyclyl alkyl groups include, butare not limited to, furan-2-yl methyl, furan-3-yl methyl, pyridine-3-ylmethyl, tetrahydrofuran-2-yl ethyl, and indol-2-yl propyl.

The term “heteroarylalkyl” as used herein refers to alkyl groups asdefined herein in which a hydrogen or carbon bond of an alkyl group isreplaced with a bond to a heteroaryl group as defined herein.

The term “alkoxy” as used herein refers to an oxygen atom connected toan alkyl group, including a cycloalkyl group, as are defined herein.Examples of linear alkoxy groups include but are not limited to methoxy,ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, and the like. Examples ofbranched alkoxy include but are not limited to isopropoxy, sec-butoxy,tert-butoxy, isopentyloxy, isohexyloxy, and the like. Examples of cyclicalkoxy include but are not limited to cyclopropyloxy, cyclobutyloxy,cyclopentyloxy, cyclohexyloxy, and the like. An alkoxy group can includeabout 1 to about 12, about 1 to about 20, or about 1 to about 40 carbonatoms bonded to the oxygen atom, and can further include double ortriple bonds, and can also include heteroatoms. For example, an allyloxygroup or a methoxyethoxy group is also an alkoxy group within themeaning herein, as is a methylenedioxy group in a context where twoadjacent atoms of a structure are substituted therewith.

The term “amine” as used herein refers to primary, secondary, andtertiary amines having, e.g., the formula N(group)₃ wherein each groupcan independently be H or non-H, such as alkyl, aryl, and the like.Amines include but are not limited to R—NH₂, for example, alkylamines,arylamines, alkylarylamines; R₂NH wherein each R is independentlyselected, such as dialkylamines, diarylamines, aralkylamines,heterocyclylamines and the like; and R₃N wherein each R is independentlyselected, such as trialkylamines, dialkylarylamines, alkyldiarylamines,triarylamines, and the like. The term “amine” also includes ammoniumions as used herein.

The term “amino group” as used herein refers to a substituent of theform —NH₂, —NHR, —NR₂, —NR₃ ⁺, wherein each R is independently selected,and protonated forms of each, except for —NR₃ ⁺, which cannot beprotonated. Accordingly, any compound substituted with an amino groupcan be viewed as an amine. An “amino group” within the meaning hereincan be a primary, secondary, tertiary, or quaternary amino group. An“alkylamino” group includes a monoalkylamino, dialkylamino, andtrialkylamino group.

The terms “halo,” “halogen,” or “halide” group, as used herein, bythemselves or as part of another substituent, mean, unless otherwisestated, a fluorine, chlorine, bromine, or iodine atom.

The term “haloalkyl” group, as used herein, includes mono-halo alkylgroups, poly-halo alkyl groups wherein all halo atoms can be the same ordifferent, and per-halo alkyl groups, wherein all hydrogen atoms arereplaced by halogen atoms, such as fluoro. Examples of haloalkyl includetrifluoromethyl, 1,1-dichloroethyl, 1,2-dichloroethyl,1,3-dibromo-3,3-difluoropropyl, perfluorobutyl, and the like.

The term “laser light,” as used herein, refers to spatially andtemporally coherent light. Laser light sources include chemical-lasers,solid-state lasers, fiber lasers, semiconductor lasers, and dye lasers.

Enumerated Embodiments

The following exemplary embodiments are provided, the numbering of whichis not to be construed as designating levels of importance:

Embodiment 1 provides a composition comprising: at least one monomer oroligomer comprising urethane acrylate; at least one monomer comprisingpentaerythritol acrylate; at least one polyester acrylate resin; and atleast one photo initiator.

Embodiment 2 provides the composition of embodiment 1, wherein theurethane acrylate comprises a urethane diacrylate.

Embodiment 3 provides the composition according to any one ofembodiments 1-2, wherein the urethane diacrylate is an aliphaticurethane diacrylate.

Embodiment 4 provides the composition according to any one ofembodiments 1-3, wherein the urethane acrylate is present in an amountof about 30 wt % to about 70 wt %.

Embodiment 5 provides the composition according to any one ofembodiments 1-4, wherein the pentaerythritol acrylate comprises apentaerythritol tetraacrylate.

Embodiment 6 provides the composition according to any one ofembodiments 1-5, wherein the pentaerythritol tetraacrylate isethoxylated.

Embodiment 7 provides the composition according to any one ofembodiments 1-6, wherein the pentaerythritol acrylate is present in anamount of about 30 wt % to about 70 wt %.

Embodiment 8 provides the composition according to any one ofembodiments 1-7, wherein the polyester acrylate resin comprises one ormore thiol groups.

Embodiment 9 provides the composition according to any one ofembodiments 1-8, wherein the polyester acrylate resin is present in anamount of about 10 wt % to about 30 wt %.

Embodiment 10 provides the composition according to any one ofembodiments 1-9, wherein the photo initiator has the formula I

wherein, M is a transition metal; and L¹, L², L³, and L⁴ are eachindependently alkyl, aryl, alkylaryl, or heteroaryl, each of which issubstituted or unsubstituted.

Embodiment 11 provides the composition according to any one ofembodiments 1-10, wherein L¹ and L² are identical.

Embodiment 12 provides the composition according to any one ofembodiments 1-11, wherein L³ and L⁴ are identical.

Embodiment 13 provides the composition according to any one ofembodiments 1-12, wherein M is titanium.

Embodiment 14 provides the composition according to any one ofembodiments 1-13, wherein L¹ is substituted or unsubstitutedcyclopentadienyl.

Embodiment 15 provides the composition according to any one ofembodiments 1-14, wherein L¹ is cyclopentadienyl.

Embodiment 16 provides the composition according to any one ofembodiments 1-15, wherein L³ is substituted aryl.

Embodiment 17 provides the composition according to any one ofembodiments 1-16, wherein L³ has the structure

Embodiment 18 provides the composition according to any one ofembodiments 1-17, wherein the photo initiator has the structure

Embodiment 19 provides the composition according to any one ofembodiments 1-18, wherein the photo initiator is present in an amount offrom about 0.01 wt % to about 1 wt %.

Embodiment 20 provides a composition comprising: about 40 wt % of amonomer comprising aliphatic urethane diacrylate; about 40 wt % ofmonomer comprising ethoxylated pentaerythritol tetraacrylate; about 20wt % of a thiol substituted polyester acrylate resin; and at least onephoto initiator having the structure

Embodiment 21 provides a method of making a polymerizable composition,comprising: combining at least one monomer comprising urethane acrylate,at least one monomer comprising pentaerythritol acrylate, and at leastone polyester acrylate resin to form a homogenous mixture; combining thehomogenous mixture with a photo initiator to form an initial mixture;and stirring the initial mixture at a temperature greater than about 30°C.

Embodiment 22 provides the method according to any one of embodiments20-21, wherein initial mixture is stirred at about 40° C.

Embodiment 23 provides the method according to any one of embodiments20-22, wherein the initial mixture is stirred for a period of about 20minutes to about 3 hours.

Embodiment 24 provides a method of polymerizing a composition,comprising: exposing the composition of claim 1-20 to laser light.

Embodiment 25 provides the method according to any one of embodiments20-24, wherein the light has an intensity ranging from about 1 mW/cm² toabout 200 mW/cm².

Embodiment 26 provides the method according to any one of embodiments20-25, wherein the composition is subjected to the light for a period ofabout 10 seconds to about 120 seconds.

Embodiment 27 provides the method according to any one of embodiments20-26, wherein the laser light has a wavelength ranging from about 400nm to about 530 nm.

Embodiment 28 provides a method of holographic printing, comprising:projecting a hologram into at least a portion of the composition ofclaim 20-27; and polymerizing the composition substantially in the shapeof the hologram.

Embodiment 29 provides the method according to any one of embodiments20-28, wherein the hologram comprises laser light with a wavelengthranging from about 480 nm to about 530 nm.

What is claimed is:
 1. A composition comprising: at least one monomer oroligomer comprising urethane acrylate; at least one monomer comprisingpentaerythritol acrylate; at least one polyester acrylate resin; atleast one photo initiator; and the polyester acrylate resin comprisesone or more thiol groups.
 2. The composition of claim 1, wherein theurethane acrylate comprises a urethane diacrylate.
 3. The composition ofclaim 2, wherein the urethane diacrylate is an aliphatic urethanediacrylate.
 4. The composition of claim 1, wherein the urethane acrylateis present in an amount of about 30 wt % to about 70 wt %.
 5. Thecomposition of claim 1, wherein the pentaerythritol acrylate comprises apentaerythritol tetraacrylate.
 6. The composition of claim 5, whereinthe pentaerythritol tetraacrylate is ethoxylated.
 7. The composition ofclaim 1, wherein the pentaerythritol acrylate is present in an amount ofabout 30 wt % to about 70 wt %.
 8. The composition of claim 1, whereinthe polyester acrylate resin is present in an amount of about 10 wt % toabout 30 wt %.
 9. The composition of claim 1, wherein the photoinitiator has the formula I

wherein, M is a transition metal; and L¹, L², L³, and L⁴ are eachindependently alkyl, aryl, alkylaryl, or heteroaryl, each of which issubstituted or unsubstituted.
 10. The composition of claim 9, wherein L¹is substituted or unsubstituted cyclopentadienyl.
 11. The composition ofclaim 10, wherein L¹ is cyclopentadienyl.
 12. The composition of claim9, wherein L³ is substituted aryl.
 13. The composition of claim 12,wherein L³ has the structure


14. The composition of claim 9, wherein the photo initiator has thestructure


15. The composition of claim 1, wherein the photo initiator is presentin an amount of from about 0.01 wt % to about 1 wt %.
 16. A method ofpolymerizing a composition, comprising exposing the composition of claim1 to laser light.
 17. A composition comprising: about 40 wt % of amonomer comprising aliphatic urethane diacrylate; about 40 wt % ofmonomer comprising ethoxylated pentaerythritol tetraacrylate; about 20wt % of a thiol substituted polyester acrylate resin; and at least onephoto initiator having the structure


18. A method of making a polymerizable composition, comprising:combining at least one monomer comprising urethane acrylate, at leastone monomer comprising pentaerythritol acrylate, and at least onepolyester acrylate resin to form a homogenous mixture; combining thehomogenous mixture with a photo initiator to form an initial mixture;and stirring the initial mixture at a temperature greater than about 30°C., wherein the polyester acrylate resin comprises one or more thiolgroups.
 19. The method of claim 18, wherein initial mixture is stirredat about 40° C.
 20. A composition comprising: at least one monomer oroligomer comprising urethane acrylate; at least one monomer comprisingpentaerythritol acrylate; at least one polyester acrylate resin; and atleast one photo initiator, wherein: the photo initiator has the formulaI

M is a transition metal; L¹, L², and L⁴ are each independently alkyl,aryl, alkylaryl, or heteroaryl, each of which is substituted orunsubstituted; and L³ has the structure


21. The composition of claim 20, wherein the urethane acrylate comprisesa urethane diacrylate.
 22. The composition of claim 21, wherein theurethane diacrylate is an aliphatic urethane diacrylate.
 23. Thecomposition of claim 20, wherein the urethane acrylate is present in anamount of about 30 wt % to about 70 wt %.
 24. The composition of claim20, wherein the pentaerythritol acrylate comprises a pentaerythritoltetraacrylate.
 25. The composition of claim 24, wherein thepentaerythritol tetraacrylate is ethoxylated.
 26. The composition ofclaim 20, wherein the pentaerythritol acrylate is present in an amountof about 30 wt % to about 70 wt %.
 27. The composition of claim 20,wherein the polyester acrylate resin comprises one or more thiol groups.28. The composition of claim 20, wherein the polyester acrylate resin ispresent in an amount of about 10 wt % to about 30 wt %.
 29. Thecomposition of claim 20, wherein L¹ is substituted or unsubstitutedcyclopentadienyl.
 30. The composition of claim 30, wherein L¹ iscyclopentadienyl.
 31. The composition of claim 20, wherein the photoinitiator has the structure


32. The composition of claim 20, wherein the photo initiator is presentin an amount of from about 0.01 wt % to about 1 wt %.
 33. A method ofpolymerizing a composition, comprising: exposing the composition ofclaim 20 to laser light.